From 8f5df046f650d33893d3f466b1a9e6865fe9c9c9 Mon Sep 17 00:00:00 2001
From: Sean Bright <sean.bright@gmail.com>
Date: Mon, 3 Dec 2018 17:41:56 -0500
Subject: [PATCH] core: Add some documentation to the malloc_trim code
This adds documentation to handle_cli_malloc_trim() indicating how it
can be useful when debugging OOM conditions.
Change-Id: I1936185e78035bf123cd5e097b793a55eeebdc78
---
main/cli.c | 55 +++++++++++++++++++++++++++++++++---------------------
1 file changed, 34 insertions(+), 21 deletions(-)
diff --git a/main/cli.c b/main/cli.c
index 653c157282..ef73ba3892 100644
--- a/main/cli.c
+++ b/main/cli.c
@@ -1781,30 +1781,43 @@ static char *handle_cli_wait_fullybooted(struct ast_cli_entry *e, int cmd, struc
#ifdef HAVE_MALLOC_TRIM
- /* BUGBUG malloc_trim() is a libc specific function. Non-portable. */
- static char *handle_cli_malloc_trim(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
- {
- extern int malloc_trim(size_t __pad) __THROW;
-
- switch (cmd) {
- case CLI_INIT:
- e->command = "malloc trim";
- e->usage =
- "Usage: malloc trim\n"
- " Try to give excess memory back to the OS.\n";
- return NULL;
- case CLI_GENERATE:
- return NULL;
- }
- if (malloc_trim(0)) {
- ast_cli(a->fd, "Returned some memory to the OS.\n");
- } else {
- ast_cli(a->fd, "No memory returned to the OS.\n");
- }
+/*!
+ * \internal
+ * \brief Attempt to reclaim unused heap memory.
+ *
+ * Users have reported that asterisk will sometimes be killed because it can't allocate
+ * more than around 3G of memory on a 32 bit system.
+ *
+ * Using malloc_trim() will help us to determine if it's because there's a leak or because
+ * the heap is so fragmented that there isn't enough contiguous memory available.
+ *
+ * \note malloc_trim() is a GNU extension and is therefore not portable.
+ */
+static char *handle_cli_malloc_trim(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+ extern int malloc_trim(size_t __pad) __THROW;
- return CLI_SUCCESS;
+ switch (cmd) {
+ case CLI_INIT:
+ e->command = "malloc trim";
+ e->usage =
+ "Usage: malloc trim\n"
+ " Try to give excess memory back to the OS.\n";
+ return NULL;
+ case CLI_GENERATE:
+ return NULL;
}
+
+ if (malloc_trim(0)) {
+ ast_cli(a->fd, "Returned some memory to the OS.\n");
+ } else {
+ ast_cli(a->fd, "No memory returned to the OS.\n");
+ }
+
+ return CLI_SUCCESS;
+}
+
#endif
static char *handle_help(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
--
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